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This paper studies stock portfolio selection problem based on varying conservative-neutral-aggressive attitudes. The return rates of stocks are characterized by fuzzy variables. The Pareto-optimal solutions are obtained by maximizing the return and minimizing the risk subject to constraints of transaction cost and value at risk. Since investors with different attitudes may have different understanding of the likelihoods of occurrence, measure Me with the ability of reflecting varying conservative-neutral-aggressive attitudes is adopted. Based on Me, the expected value of fuzzy return and the lower absolute deviation are used to quantify the return and risk levels of a portfolio respectively. Then the ɛ-constraint method is employed to obtain the efficient frontier. Finally, an empirical study is carried out using the data of 10 stocks in Chinese stock market. Sensitivity comparisons are conducted to demonstrate the effectiveness of the proposed model. The results show that different frontiers can be obtained under different attitudes, confidence levels and values at risk.

Chronic restraint stress can induce depressive and anxiety-like behavior and neurophysiological disturbances. The social living shows the health-promoting and stress-protective effects on both human and animal. However, whether group housing exerts effects on development of depression and anxiety induced by chronic restraint treatments and its detailed neuroendocrine mechanism remain unclear. Following repeated restraint, the anxiety and depression-like behaviors of single and group housing mice were examined using the elevated plus-maze, open field test and forced swimming test. The levels of central oxytocin (OT) expression in the paraventricular nucleus (PVN), glucocorticoid receptors (GR) in the hippocampus and serum OT and corticosterone (CORT) were also measured using immunohistochemistry and ELISA methods. Our results show that chronic restraint significantly decreased time in open arm of elevated plus maze and increased immobility time in forced swimming test in single-housed mice. However, chronic restraint exerted no effects on these aspects in group-housed mice. Accompanying the changes of behaviors, chronic restraint up-regulated levels of serum CORT and reduced the hippocampus GR in single-housed animals, but did not change these measures in group-housed mice. Furthermore, repeated restraint had no effect on OT levels in these two housing conditions although group-housing significantly increased the PVN OT levels. Taken together, these results provide substantial evidence that group housing can reduce levels of anxiety and depression induced by chronic restraint stress in mice. The elevation of central GR and OT, and decrease of circulating CORT may possibly be involved in these buffering effects.

Organochlorine pesticides (OCPs, including DDT, HCH and HCB) and six indicator polychlorinated biphenyls (PCB 28, 52, 101, 138, 153, and 180) were measured in water, sediment, zooplankton, fish and Chinese softshell turtle (Pelodiscus sinensis) from Gaobeidian Lake, which is located in the effluent of Gaobeidian wastewater treatment plant (WWTP) in Beijing, China. DDTs were dominant except for in water. In water, the concentrations of DDTs (6.22 ng l(-1)) and HCHs (18.0 ng I`) were less than the limits (1000 ng 1-1 for DDTs and 5000 ng l(-1) for HCHs). However, PCBs concentration (20.8 ng l(-1)) exceeded the limit (14 ng l(-1)) suggested by the United States Environmental Protection Agency (USEPA). The high ratio of p,p'-DDT/DDTs (0.80) in water suggested that DDTs had recently been discharged into the ambient environment despite a longtime ban in China. For fish and Pelodiscus sinensis, the accumulation patterns of OCPs and PCBs were different in muscle and liver. And HCB and PCB 153 were significant different in different species (p < 0.05). PCBs were dominated by PCB 52 in zooplankton, but by PCB 138 and 153 in Pelodiscus sinensis. The highest food web magnification factor (FWMF) was 4.83 for pp'-DDT and the second highest was 4.36 for PCB 101 in Gaobeidian Lake. As compared with the other studies, biomagnification in the present study was not obvious. Trophic levels and age were two important factors that might contribute to the bioaccumulation in the present study. (c) 2008 Elsevier Ltd. All rights reserved.

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured by a gas chromatography–mass spectometry (GC–MS) in some edible fish from Huairou Reservoir and Gaobeidian Lake in Beijing, China. The concentrations of OCPs and PCBs were higher in fish (except Misgurnus anguillicaudatus) from Gaobeidian Lake than in those from Huairou Reservoir. The average concentrations of HCHs, DDTs and PCBs in fish ranged from 0.58 to 8.48, 7.54 to 88.3, below limit of detection (nd) to 22.7 ng/g wet weight, respectively. β-HCH, p,p′-DDE and PCB153 were the most abundant compounds among HCHs, DDTs and PCBs, respectively. Risk assessments of OCPs and PCBs for humans were estimated according to three different guidelines. The results indicated that fish intake would not pose a health risk to humans with a consumption of 7.4 ± 8.6 g/person day according to the acceptable daily intake (ADI) and minimal risk level (MRL) in the two environments. However, the hazardous ratio of the 95th percentile for PCBs in fish from Gaobeidian Lake exceeded 1, which suggested that daily exposure to PCBs had a lifetime cancer risk of greater than 1 in 1,000,000.

Three types of SiO2 ultrafine particles were used to investigate the fluidization behavior in a fluidized bed with sound excitation. It has been shown that agglomerate size tends to reduce with an increase in sound pressure level. At a given sound pressure level, there exists a critical sound frequency (fc). Agglomerate size is decreased with increasing sound frequency as sound frequency less than fc. Whereas, agglomerate size intends to grow with an increase in sound frequency as sound frequency exceeds fc. A mathematic model to predict the agglomerate size has been developed based on energy balance between the agglomerate collision energy, the energy arising from sound wave, and cohesive energy. The model can predict qualitatively the effects of sound frequency and sound pressure level on agglomerate size.

The starch and cyclodextrin were selected as the precursors and the mixture of surfactant and tetraethyl orthosilicate (TEOS) as template to prepare mesoporous carbon. The result showed that a bimodal pore size distribution in mesoporous carbon derived from starch appeared; one was around 3.4 nm and the other ranged from 3.8 to 16.2 nm. However, there existed a concentrated pore size distribution from 3.2 to 4.2 nm in mesoporous carbon derived from cyclodextrin. The different molecular structure of starch and cyclodextrin and their polymerization process in the presence of sulfur acid were responsible for the resulted mesoporous carbon structure; the starch could polymerize by head to head or side by side, but the cycleodextrin was only polymerized by head to head.

Fifteen novel (E)-alpha-(methoxyimino)-benzeneacetate derivatives, the analogues of strobilurins, which contain two pharmacophoric substructures of (E)-methyl methoxyiminoacetate moiety and 1,3,4-oxadiazole ring were stereoselectively synthesized. It was first found that the coupling reaction could give stereoselectively the key intermediate (E) and (Z)-methyl 2-(hydroxyimino)-2-o-tolylacetate 2 with a ratio of 14:1. The preliminary bioassays indicated that all the compounds 1 showed potent fungicidal activity against Rhizoctonia solani, Botrytis cinereapers, Gibberella zeae, Physalospora piricola and Bipolaris mayclis, and all of the tested compounds 1a-1o had more potent fungicidal activities against R. solani than Kresoxim-methyl.

Five sewage-treatment plants were studied for 1 year including the two plants of the Beijing Gaobeidian Sewage Treatment Factory, the largest activated-sludge scheme in China, with a treatment capacity of one million tons of sewage daily. Vorticella convallaria , Epistylis plicatilis , Aspidisca sulcata and Arcella hemisphaerica occurred frequently at all five plants and usually appeared in large numbers in the mixed liquor. Rotifers occurred frequently and in moderate numbers at all five plants. The two plants at Gaobeidian had a high degree of similarity, and the fauna structure of Beixiaohe Plant was similar to that of Fangzhuang. Rotifers showed a negative association with the reduction of BOD 5 , COD and suspended solids removal at two plants. The appearance of many Arcella hemisphaerica was associated with good settlement at two plants.